Clutter rejection
From Glossary of Meteorology
clutter rejection
Any of a variety of processes or techniques to eliminate the effects of unwanted signals (clutter) in radar measurements.
Clutter rejection most commonly refers to the filtering of the received signal to reject components that have specified phase or amplitude characteristics. In meteorological Doppler radar signal processing, for example, one approach to clutter rejection is to reject signals with Doppler velocities near zero, because stationary scattering objects induce no Doppler shift.